Many times in workplaces - whether office or nba - a young college kid comes into an older workplace and everyone imparts that knowledge on the kid. As the kid grows and learns, and often times, becomes better than his mentors, his mentors don't properly recognize this, still think of him as the naive kid, and don't give him requisite responsibility and compensation, so the kid leaves.
The opposite has happened here. Rondo was that kid but it is clear that Danny and doc realized the kid was the best player and gave him more power and more compensation to the point where it is now his team (on offense). It seems like ray still sees rondo as that kid, and ray has mentioned in the past how rondo used to follow him around and do his routine w him and doesn't know why he stopped. Sounds like ray is the sole old guy who never came to terms w rondos emergence and that is the heart of a lot of the problems right there.
Ray won't have the same problems w lebron because ray never knew lebron as a kid and ray can be ok w taking a backseat to lebron. He can't stomach taking a backseat to that kid who he tried to mold and who eventually spurned his training ways for his own.
While hurtful and surprising to us that he is going to our rival, ray was always the most mercenary of the bunch. Only guy who had played on two teams before the celtics, any sense of loyalty in the nba was lost to him at a much earlier age than the other big four, and if he developed a new sense of loyalty w boston, it wasn't a strong one and was probably destroyed when he was told he was traded, and buried when they didn't go after him as hard as kg. doesn't matter that kg is clearly better...they are both hall of famers and part of the big three (and in the big three, everyone sacrificed for the greater good..together), so why weren't they both consulted at the same time to come back? Thats probably how ray was thinking, and if you are thinking like that, the superficial love from south beach probably seemed pretty good.
Ray will regret his decision at some point, and my guess is that point will be training camp w a coach that is not doc and w players that were prima donnas before their title and now will be even worse. The cracks bout rays celtcs will prob sting. And ray will realize he screwed up...but it will happen too late.
And so it goes.